ncl_gclose_gks man page

A call to gclose_gks insures that the graphics package is properly terminated. No graphics calls depending on GKS should be made during the time that GKS is closed. If output to a CGM has been the exclusive requirement of the graphics job, and the SPPS entry c_opngks has been used to open GKS and to open and activate a CGM workstation, then c_clsgks can be used to deactivate and close the CGM workstation, and to close GKS, making a direct call to gclose_gks unnecessary in that case.